The fiancée of Laurent Bonomo wrote yesterday of her grief and wish for revenge in a heartfelt message posted on the internet as anxious parents in France urged their offspring to come home from Britain.

Mary Bertez, who intended to marry Laurent Bonomo after he returned to France, wrote on his profile page on Facebook, the social networking website, that she thought about her fiancé “every second”.

Her grief was echoed by dozens of friends who described Mr Bonomo and Gabriel Ferez as being “full of life and looking forward to getting home”.

Miss Bertez, a student at the University of Valenciennes, referred to her boyfriend as her “doudou” - her teddy bear.

“My love, unfortunately I was not there that night, we who are always together,” she wrote yesterday afternoon. “I do not stop thinking about you every second. . . I have lived ten months of happiness that I never lived until then. Today you left.

“I will give all necessary information for the investigation, my dear, so that you can be avenged. I love my ‘dou-dou’ from the bottom of my heart.”

She wrote her message as fearful families in France asked colleges to cut short their children’s student placements in Britain.

Claude-Gilles Dussap, the director of the prestigious Clermont-Ferrand Polytechnic - affiliated to the École Polytechnique, which was founded in 1794 and is regarded as France’s foremost engineering institution - said families had expressed acute concern for the safety of their children.

“We’ve had families ringing to tell us to bring their children back from Britain and other European countries,” Mr Dussap told The Times. “This is going to leave its mark. There will obviously be a problem with England now. We are going to have to work very hard to overcome that and that is why we need the investigation to get to the bottom of this as quickly as possible.”

Mr Dussap said that Mr Bonomo and Mr Ferez were popular students with many friends, and promising futures in engineering . “I knew Laurent Bonomo very well because he was head of the students’ union for a year and we spent two or three hours a week together at this very table,” he said, sitting in his first-floor office.

The polytechnic has set up a psychological unit to help students to overcome their shock.

A close friend of the two men said that they had been in good spirits when he spoke to them last week. Antoine Galloux, 23, said that they were preparing to resume their lives in France. “Both Gabriel and Laurent were looking forward to getting back to France at the end of July, ” he said. “Laurent was going to continue his studies in bioengineering in Lille, while Gabriel wanted to start a doctorate back in Clermont-Ferrand.”

Mr Galloux broke down in tears as he described Gabriel as his best friend. “We were extremely close. None of us can believe what happened. No one would expect something like this to happen in a city like London.”

The news of the students’ murders reached the Clermont-Ferrand campus on Monday, but friends refused to believe the rumours. The gradual realisation of the truth is played out on Mr Bonomo’s Facebook profile. Caroline Durand, a fellow student, pleaded with her friend to scotch rumours as “damned stupidity”. She wrote: “Reassure me!”

The truth was confirmed by Aurelien Jeandot, another friend, who said that Mr Bonomo’s mother and fiancée had called him on Sunday night because they were worried. Mrs Bonomo called again on Monday afternoon to confirm the worst. Students at the university were overwhelmed when the death was announced there on Tuesday.

Murati Cedric, a friend from school, said that he was sure Mr Bonomo would rest in peace. “You were one of my best pals, and I am certain that all those who knew you from this time will join with me to say that you are a great sort, interesting and funny. We will not forget you.”

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